JPH08139118A - Semiconductor device and production thereof - Google Patents

Abstract

PURPOSE: To obtain a semiconductor device, and production method thereof, in which a hollow part can be formed above an element using only a sealing resin. CONSTITUTION: A soluble resist 8 is applied onto an element 2 mounted on a board 1 and then a part thereof is removed. It is then coated with a sealing resin 8 and the soluble resist 8 is dissolved and removed partially from the uncoated part to leave a window 10. Subsequently, the window 10 is covered with a sealing resin 9a thus forming a hollow part 11 above the element 2. Since only a sealing resin is required, the material cost is reduced and since only the surface of the element is made hollow, the size can be reduced easily.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvements in a semiconductor device in which an element such as a surface acoustic wave element is mounted on a substrate and a method for manufacturing the same.

[0002]

2. Description of the Related Art In a surface acoustic wave element, if foreign matter is present on the propagation surface portion, the propagation of the surface wave is adversely affected and desired characteristics are impaired. Therefore, a hollow sealing package is used in order to bring the propagation surface of the element into a non-contact state.
A ceramic package or a metal package is mainly used as the hollow sealing package. Although they are highly reliable, they have the disadvantage of high cost. In addition, in recent years, methods of covering the element (chip) with a lid and methods of covering the area around the lid with resin have been proposed in order to make low-cost ones. is there. However, in these methods, the cost of the lid is higher than that of a simple resin-sealed package, the number of steps of covering the lid is increased, and the productivity is deteriorated.

[0003]

Recently, there has been proposed a hollow sealing package made of a resin material as shown in FIG. 4 without using a ceramic or metal package. This is because the chip 2 mounted on the substrate 1 is covered with an insulating film 4 so as to leave a hollow portion 3, and a resin 5 is applied from above the adhesive film 6 via an adhesive layer 6, and the resin 5 is cured to form a hollow. It is a package.

In the above method, the film and the resin can be composed of materials which are generally sold in large quantities on the market.
There are advantages that the cost can be reduced and the size can be reduced. However, since the film 4 must be covered so as to cover the bonding wire 7 that connects the chip and the substrate side, and the surrounding area is covered with the resin 5, there is a wasteful portion.

[0005]

SUMMARY OF THE INVENTION The main object of the present invention is to provide a semiconductor device and a method of manufacturing the same, in which a hollow portion can be formed only by a sealing resin without using the above film. In particular, it is to further reduce the cost and downsize.

[0006]

A method of manufacturing a semiconductor device according to the present invention comprises a step of applying a soluble resist to a place in a semiconductor device where a hollow structure is to be formed, and the applied resist except a part thereof. A step of covering with a first resin package material; a step of supplying a solvent that dissolves the soluble resist from a portion not covered with the resin package material to remove the soluble resist; and a portion including the portion. The gist is that it comprises a step of covering with a second resin package material to complete the hollow portion.

In the semiconductor device according to the present invention, the soluble resin applied to the elements on the substrate is applied so as to cover a part of the soluble resist, and the soluble resist is removed by dissolution from the part. The second feature is that the second resin package material is applied so as to cover the window portion left after the above.

[0008]

In the method of manufacturing a semiconductor device described above, a semiconductor device having a hollow structure can be obtained at low cost by applying simple steps. In addition, the semiconductor device configured by the above manufacturing method can be downsized because only the surface of the element can be hollow.

[0009]

1A to 1D show a first embodiment of a method for manufacturing a semiconductor device according to the present invention. The manufacturing process will be described below. First, a resist 8 (resin) that is soluble even after curing is applied onto the surface acoustic wave element 2 on the substrate 1,
It is dried by heating and cured (FIG. 1 (a)). A sealing resin 9 to be a package is applied thereon (FIG. 1).
(B)). At this time, at least one place where the resist 8 is exposed is provided. After the sealing resin 9 is cured by heating, the resist 8 applied on the element 2 is removed using a solvent such as acetone or alcohol (FIG. 1C). Further, by sealing the window portion 10 left after removing the resist 8 with the resin 9a, a minute hollow portion 11 is formed, and a hollow package that does not hinder the surface wave of the surface acoustic wave element can be formed. (FIG. 1 (d)). The resin 9a for sealing the window 10 may be different from the resin 9.

FIG. 2 shows a second embodiment of the present invention. First, the element 2 is coated with a resist 8 (resin) that is soluble even after curing, and is heated and dried to cure (FIG. 2A).
On top of that, an ultraviolet curable (photocurable) resin 12 for temporary sealing
Is applied (FIG. 2 (d)). At this time, at least one place where the resist is exposed is provided. UV curable resin 1
After 2 is cured by ultraviolet rays, the resist 8 coated on the element 2 is removed using a solvent such as acetone or alcohol (FIG. 2C). UV curable resin 12
Is generally inferior in moisture resistance and inferior in heat resistance. Therefore, a resin 13 which is superior in moisture resistance and heat resistance is applied thereon, and the window portion 10 after removing the resist is covered. Then, it is cured by heating and sealed (FIG. 2D).

FIG. 3 shows a third embodiment of the present invention. First, the resin 8 is applied onto the element 2 and left in a liquid state without being heated (FIG. 3A). An ultraviolet curable (photocurable) resin 12 for temporary sealing is applied thereon (FIG. 3).
(B)). In this case, since the two resins have different properties, they do not mix easily. At this time, 1
Provide more than one place where the resist is exposed. After curing the ultraviolet curable resin 12 with ultraviolet rays, acetone,
The resin 8 applied on the element is removed using a solvent such as alcohol (FIG. 3C). Since the ultraviolet curable resin is generally inferior in moisture resistance or inferior in heat resistance, a resin 14 having further excellent moisture resistance or heat resistance is applied onto the ultraviolet curable resin to remove the resist-removed window portion 10. By blocking
It is heat-cured and sealed (FIG. 3D).

[0012]

As described above in detail, according to the semiconductor device and the method of manufacturing the same of the present invention, the following effects can be obtained. (1) Since the package is composed only of the sealing resin, the material cost is low. (2) Since only the surface wave propagation path on the element can be made hollow, size reduction is easy. (3) Since devices of various sizes can be dealt with by slightly changing the method of applying the sealing resin, it is effective for high-mix low-volume production.

[Brief description of drawings]

FIG. 1 is a manufacturing process diagram of a semiconductor device according to a first embodiment of the invention.

FIG. 2 is a manufacturing process diagram of a semiconductor device according to a second embodiment of the present invention.

FIG. 3 is a manufacturing process diagram of a semiconductor device according to a third embodiment of the present invention.

FIG. 4 is a sectional view of a conventional semiconductor device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Element 3 Hollow part 4 Insulating film 5 Sealing resin 6 Adhesive layer 7 Bonding wire 8 Soluble resist 9,9a Sealing resin 10 Window part 11 Hollow part 12 UV curable resin for sealing 13,14 Sealing resin

Claims (3)

[Claims] 1. A step of applying a soluble resist to a place where a hollow structure is to be formed in a semiconductor device, a step of covering the applied resist except a part thereof with a first resin package material, and the resin package. A step of supplying a solvent that dissolves the soluble resist from a portion not covered with the material to remove the soluble resist, and a portion including the portion is covered with a second resin package material to complete a hollow portion. And a method of manufacturing the same. 2. The second resin package material covers the entire first resin package material.
A method of manufacturing a semiconductor device according to item 1. 3. A first resin package material applied so as to cover a part of the soluble resist applied to the element on the substrate, and the soluble resist left after the soluble resist is removed from the part. And a second resin package material applied so as to cover the window portion.